Manifold Absolute Pressure (Map) Sensor
- MAP sensor is mounted on the engine cowl, above TBI unit (1.6L) or on the air cleaner assembly (2.0L). See Figure . Map sensor is connected to intake manifold vacuum. When engine is off, MAP sensor functions as a Barometer (BARO).
- To check sensor, turn ignition to ON position with engine off. Backprobe MAP sensor connector and measure voltage between terminals "A" (5-volt reference) and "C" (sensor ground). See Fig 1 .
- If 5 volts is not present, check continuity of 5-volt reference and ground circuits between ECM and sensor. Measure voltage at sensor connector terminal "B" (MAP signal).
- Voltage should be as specified in MAP SENSOR VOLTAGE SPECIFICATIONS table. If voltage is not within specification, replace MAP sensor. If voltage is within specification, connect a hand-held vacuum pump to sensor and apply 10 in. Hg. Voltage should change immediately and be 1.2 volts less than previous reading.
- If voltage is not within specification or changes slowly, replace sensor. If a Scan tester is used either voltage or kPa (kilopascals) pressure will be displayed.
MAP SENSOR VOLTAGE SPECIFICATIONS
| Altitude (Feet) | Signal Voltage (Terminal "B") |
|---|---|
| 1,000 or less | 3.8-5.5 |
| 1,000-2,000 | 3.6-5.3 |
| 2,000-3,000 | 3.5-5.1 |
| 3,000-4,000 | 3.3-5.0 |
| 4,000-5,000 | 3.2-4.8 |
| 5,000-6,000 | 3.0-4.6 |
| 6,000-7,000 | 2.9-4.5 |
| 7,000-8,000 | 2.8-4.3 |
| 8,000-9,000 | 2.6-4.2 |
| 9,000-10,000 | 2.5-4.0 |